Over the past year, the Trump administration has ramped up its attacks on immigrants and immigration policy as a whole in an attempt to restrict significantly the numbers of immigrants entering the United States each year. Among the primary lines of attack has been an assault on family-based migration—the ability of citizens and green card holders to reunite with their family members—under the misguided notion that the nation must “end chain migration.”

Given the Trump administration’s attempt to limit the ability of people to bring in their family members, it’s worth exploring why America’s immigration policies are rooted in family ties. Far from what the White House calls “an antiquated system of family ties,” family reunification has been a cornerstone of immigration law since the late 1800s. Understanding why immigration policy has always privileged family ties helps clarify why the category remains so critical today.

Early immigration restrictions and family reunificationThe first federal attempts to limit immigration came in the late 19th century, with a series of laws that targeted Asian immigrants—such as the Chinese Exclusion Act of 1882—and restricted laborers. The Alien Contract Labor Law of 1885, which restricted the ability of most immigrants to enter the United States for the purpose of employment, specifically exempted family members from its exclusions. Likewise, the Immigration Act of 1917, which imposed a literacy test meant to curtail overall immigration to the United States, exempted parents, grandparents, wives, and daughters from the test. And the Emergency Quota Act of 1921 and the Immigration Act of 1924 allowed spouses and minor children to enter outside of numerical limitations. These latter two acts laid the foundations for the national origins quota system, which selected immigrants based on race and national origin, privileging immigrants from northern Europe, limiting those from southern Europe, and excluding Asian and African immigrants entirely.

From the earliest restrictions on immigration, then, Congress explicitly recognized the importance of keeping families together and carved out a place for them.

During and after World War II, family reunification became one of the key factors in ending the policy of Asian exclusion. Starting in 1945, Congress passed a series of laws benefiting so-called war brides from Asia, the spouses and fiancées of American soldiers who were barred from entering the United States because of their race or nationality. According to Sen. Richard Russell Jr. (D-GA) in 1945, this change was “the least we can do for the men who fought our wars overseas … and who now wish to have their wives join them in this country.”

Legislation to admit Asian war brides helped crack open the doors to permitting the entry of Asian immigrants more generally, and it laid the groundwork for appeals to keep families together to become the dominant way for reformers to challenge racially exclusionary immigration policy.

Family reunification as the bedrock of immigration policyIn 1965, Congress passed the Immigration and Nationality Act, a sweeping law that did away with the national origins quotas and put in place the modern system of immigrant admissions the country largely still has today—a system weighted toward family reunification, with a lesser emphasis on employment-based migration. In fact, the act granted 74 percent of all permanent visas to family reunification categories. Prior to 1965, visas were split equally between employment and family reunification categories.

So why did Congress move to a heavily family-based system in 1965? A number of scholars have focused on the backward-looking nature of this change, arguing that a group of conservative legislators such as Rep. Michael Feighan (D-OH) imposed the family-based system at the last minute, as a way of dismantling the overt racism of the national origins quotas while still keeping future immigration largely white and European. As Rep. Emanuel Celler (D-NY), a co-sponsor of the 1965 act who had been fighting to dismantle the racial quotas since his first speech in Congress in 1924, put it, “[S]ince the peoples of Africa and Asia have very few relatives here, comparatively few could immigrate from those countries.” Sen. Sam Ervin (D-NC) put it even more bluntly: “[T]he bill does not open the doors for the admission of all the people all over the face of the earth.”Yet while some members of Congress did indeed view a family-based system as a way of keeping the doors closed to most of the world, this is only a portion of the story. Just as the issue of war brides helped Congress dismantle Asian exclusion, highlighting the plight of families kept apart from one another became the primary way in which reformers fought against the national origins quota system. To take one example, President Dwight D. Eisenhower argued in 1957 that “[t]here is increasing apprehension among our citizens … about the moral principle involved when we keep children and spouses apart from fathers and husbands for many years by immigration barriers.”

Congress would go on to pass stopgap laws in 1957, 1959, 1961, and 1962—even before the full overhaul of immigration policy in 1965—to allow in family members kept out of the United States by the quota system. By the time that the Lyndon Johnson administration proposed the first draft of what would ultimately become the 1965 act—a draft that kept the focus equally split between employment- and family-based migration—it was all but inevitable that family reunification would become the dominant force in immigration law. As Sen. Leverett Saltonstall (R-MA) argued during the 1965 debates, “all too often … we must report to our constituents the discouraging news that delays, often of many years’ duration, must be anticipated before families can be brought together.”

In signing the 1965 act into law, President Lyndon B. Johnson called it “not a revolutionary bill.” Of course, this was a vast understatement. As the Pew Research Center has found, the act ushered in a “modern immigration wave,” which brought nearly 60 million people to the United States. Without the law, the nation’s population would be smaller, older, less diverse, and far less able to cope with the challenges of the modern labor force and wave of Baby Boomer retirements.ConclusionEchoing conservative legislators in 1965, the Trump administration is currently attempting to reshape immigration policy in a way that—by proposing to cut family-based immigration categories, among others—would substantially restrict the ability of black, Hispanic, and—to a lesser extent—Asian and Pacific immigrants to come to the United States. And as with those who believed that substituting the race-based quotas with family reunification would keep in place racial restrictions without overtly saying so, the Trump administration has proposed its restrictions using facially neutral language such as wanting to “protect the nuclear family”—code for cutting the ability of most family members to enter the country—and implement a “merit-based system”—code for slashing overall immigration numbers.

As Congress debates the future of immigration policy, it is important to remember that the creation of the family-based immigration system in 1965 was more than just an attempt to stem the tide of nonwhite immigrants after 1965. As historian Carly Goodman so aptly puts it, “Family unity was a strong shared value that transcended partisan and ideological divides, despite its different interpretations and meanings to different people.”

Remembering that family unity has always been a bedrock of American immigration policy, as well as a way to illustrate the hypocrisy of exclusionary policies based on race and national origin, helps clarify the stakes of today’s debate and expose just how far outside the mainstream the current attacks on family exist.

Philip E. Wolgin is the managing director of Immigration Policy at the Center for American Progress.